Objectives:

Prosthetic joint infections represent an infrequent but feared complication of total joint arthroplasty, leading to a substantial postoperative morbidity, prosthesis failure and, in some cases, to death. Moxifloxacin is a new fluoroquinolone with a broad antibacterial spectrum and improved activity against gram positive microorganism and anaerobes; it shows an enhanced potency against methicillin-susceptible and -resistant isolates of S. aureus and S. epidermidis, if compared with the older fluoroquinolones. Penetration of moxifloxacin in bone has not still assessed. The main purpose of this study was to determine moxifloxacin levels in serum and bone following oral administration of single and multiple oral doses of 400 mg of the drug, to evaluate its potential use in perioperative orthopaedic prophylaxis.

Methods:

Thirty consecutive patients, undergoing routine total knee arthroplasty were enrolled in this study. Three groups of 10 patients each were formed. Group A received moxifloxacin os 400 mg 2 h ± 30 preoperatively. Group B received moxifloxacin os 400 mg 4 h ± 30 preoperatively. Group C received moxifloxacin os 400 mg 14 h preoperatively, followed by a second dose 2 h± 30 preoperatively. During surgery, at the time of bone removal, a blood sample and aliquots of cortical-cancellous bone were collected and moxifloxacin concentrations were measured by high performance liquid chromatography.

Results:

The mean plasma, cancellous and cortical bone concentrations were respectively:

Group A:

3.45, 1.89 and 1.43 mg/mL.

Group B:

3.73, 1.81 and 1.56 mg/mL.

Group C:

6.26, 2.97 and 2.54 mg/mL.

Conclusions:

These data show good penetration of moxifloxacin in both cancellous and cortical bone with higher serum and bone concentrations obtained after two doses of the drug (group C). Therefore, moxifloxacin may be considered in perioperative orthopaedic prophylaxis and repeated administrations should be preferred to achieve maximum antibacterial activity at the site of surgery.